Influence of aging treatment on microstructure and properties of 7A55 aluminum alloy

doi:10.13251/j.issn.0254-6051.2021.09.020

Abstract

Abstract: Influence of aging treatment on microstructure evolution and properties of 7A55 aluminum alloy was investigated. The microhardness, mechanical properties and electrochemical corrosion behavior were tested. The TEM microstructure and corrosion morphology were characterized. The results indicate that the experimental 7A55 aluminum alloy after solution treatment has higher hardening rate. After aging at 160 ℃ for 12 h, the hardness reaches the peak (87 HV0.5) from 56 HV0.5 in the solution treated state, i.e., increased by 55.36%, and the hardening rate in early aging stage is very high. Pre-aging (PA) treatment inhibits the natural aging (NA) effect and improves the bake hardening (BH) response. The yield strength under PA+NA state after BH treatment reaches 475 MPa with an increment of 190 MPa, which improves 66.67%, and the elongation reaches 12.5%. The precipitated particles under PA+NA+BH state are finer and uniformly distributed, with the diameter in the range of 10-15 nm. The PA+NA+BH state alloy has the highest corrosion potential (－1.032 V, vs SCE), the least corrosion pits and the best corrosion resistance, with the average corrosion depth being about 33 μm.

Key words: 7A55 aluminum alloy, aging treatment, microstructure, microhardness, electrochemical corrosion property

CLC Number:

TG156

Ding Xuan, Gan Yurong, Jiang Aijuan, Li Hui, Yang Mingqiu. Influence of aging treatment on microstructure and properties of 7A55 aluminum alloy[J]. Heat Treatment of Metals, 2021, 46(9): 120-123.

References

[1]Miller W S, Zhuang L, Bottema J, et al. Recent development in aluminum alloys for the automotive industry[J]. Materials Science and Engineering A, 2000, 280(1): 37-49.
[2]Hirsch J. Recent development in aluminum for automotive applications[J]. Transactions of Nonferrous Metals Society of China, 2014, 24(7): 1995-2002.
[3]Henriksson F, Johansen K. On material substitution in automotive BIWs-from steel to aluminum body sides[J]. Procedia CIRP, 2016, 50: 683-688.
[4]杨守杰, 戴圣龙. 航空铝合金的发展回顾与展望[J]. 材料导报, 2005(2): 76-80.
Yang Shoujie, Dai Shenglong. A glimpse at the development and application of aluminum alloys in aviation industry[J]. Materials Review, 2005(2): 76-80.
[5]Cao C, Zhang D, Zhuang L Z, et al. Improved age-hardening response and altered precipitation behavior of Al-5.2Mg-0.45Cu-2.0Zn alloy with pre-aging treatment[J]. Journal of Alloys and Compounds, 2017, 691: 40-43.
[6]Yang R X, Liu Z Y, Ying P Y, et al. Multistage-aging process effect on formation of GP zones and mechanical properties in Al-Zn-Mg-Cu alloy[J]. Transactions of Nonferrous Metals Society of China, 2016, 25(5): 1183-1190.
[7]许晓静, 王子路, 陆文俊, 等. 固溶-大变形-时效下7085铝合金的强化机理[J]. 稀有金属材料与工程, 2017(4): 1008-1012.
Xu Xiaojing, Wang Zilu, Lu Wenjun, et al. Strengthening mechanisms of 7085 aluminum alloy by solution-large deformation-aging[J]. Rare Metal Materials and Engineering, 2017(4): 1008-1012.
[8]Chen S Y, Chen K H, Peng G S, et al. Effect of heat treatment on hot deformation behavior and microstructure evolution of 7085 aluminum alloy[J]. Journal of Alloys and Compounds, 2012, 537: 338-345.
[9]Bennett T A, Petrov R H, Kestens L A I. Effect of particles on texture banding in an aluminium alloy[J]. Scripta Materialia, 2010, 62(2): 78-81.
[10]Jiang F L, Zurob H S, Purdy G R, et al. Characterizing precipitate evolution of an Al-Zn-Mg-Cu based commercial alloy during artificial aging and non-isothermal heat treatments by in situ electrical resistivity monitoring[J]. Materials Characterization, 2016, 117: 47-56.

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